Optimization Of Arachidonic Acid Production Through Fermentation

Abstract

Arachidonic acid (ARA) is an omega-6 fatty acid (C20:4n-6) needed for improving infant memory and eyesight, and an important supplement in infant formula. This project aimed to develop a process to produce ARA from Mortierella alpina strain MA2-2 by 1) optimizing the production medium and 2) applying strain improvement techniques. The optimized medium for MA2-2 resulted in 19–22 g L-1 biomass, 30–35 % oil%, 33–42% ARA content and 2.1–2.5 g L-1 ARA concentration. Compared to the original medium, this was an improvement of at least 0.9, 0.875, 0.32, 3.7 times, respectively. Random mutagenesis was conducted using UV, cerulenin and staining reagent TTC. However, the mutants did not exhibit significantly beneficial phenotypes. High-temperature ALE was performed on wild-type MA2-2 for up to 90 days (45 ALE cycles). The evolved strain showed greater thermotolerance with ARA final productivity of 0.421 ± 0.04 g L-1 d-1, 27.6% higher than the original strain.